1. Field of the Invention
This application relates to lubricating oil compositions containing hydroxy polyether amines which contribute dispersancy and detergency to the compositions.
Lubricating oil compositions, particularly for use in internal combustion engines, have long performed many functions other than simply lubricating moving parts. Modern-day, highly compounded lubricating oil compositions provide anti-wear, anti-oxidant, extreme-pressure and anti-rust protection in addition to maintaining the cleanliness of the engine by dispersancy and detergency. Many lubricating oil additives are well known for accomplishing theses functions. For maintaining engine cleanliness, a well-known class of ashless detergents which have been found to be particularly useful are polyoxyalkylene carbamates. U.S. Pat. Nos. 4,160,648 and 4,247,301 disclose and claim fuel compositions containing certain poly(oxyalkylene)aminocarbamates and polyoxyalkylene polyamines as deposit control additives. While, in general, deposit control additives are not believed to be useful dispersants for lubricating oil compositions; generally, certain aminocarbamates and certain polyether amines are useful in this regard.
2. Prior Art
Polyether amine-type fuel additives for deposit control and lubricating oil dispersancy are well-known but have traditionally been surfactant-type molecules having a large, non-polar hydrophobic end or "tail", for instance, a hydrocarbyl capped polyether moiety, and a polar, hydrophilic amine or polyamine end. Examples of these type of compositions may be found in U.S. Pat. No. 4,233,168; U.S. Pat. No. 4,160,648; U.S. Pat. No. 4,438,022; U.S. Pat. No. 4,537,693. In the present invention, however, a composition has been discovered which in lubricating oil functions as a dispersant and detergent additive which has a single hydroxyl group in the non-polar hydrophobic portion of the molecule. These additives contain block co-polymer polyethers in which there is no hydrocarbyl cap.